Auth bypass in Umbraco Umbraco-Cms
CVE-2026-31832
Umbraco is an ASP.NET CMS. From 14.0.0 to before 16.5.1 and 17.2.2, A broken object-level authorization vulnerability exists in a backoffice API endpoint that allows authenticated users to assign domain-related data to content nodes without proper authorization checks. The issue is caused by insufficient authorization enforcement on the affected API endpoint, whereby via an API call, domains can be set on content nodes that the editor does not have permission to access (either via user group privileges or start nodes). This vulnerability is fixed in 16.5.1 and 17.2.2.
Vulnerability class: IDOR (Insecure Direct Object Reference)
EPSS: 0.002 (7.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.
Affected products
- Umbraco Umbraco-cms — versions >= 14.0.0, < 16.5.1, >= 17.0.0, < 17.2.0
- Umbraco Umbraco_cms
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-31832?
- CVE-2026-31832 is a medium-severity vulnerability in Umbraco Umbraco-Cms, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.4/10. Published 2026-03-10.
- How severe is CVE-2026-31832?
- Medium severity. CVSS v3 base score is 5.4 out of 10.